The present invention relates to a sequence controller, and more particularly to a write-only sequence controller of a stored program type with which data programing and its modification can be done extremely easily and rapidly.
A conventional sequence controller has a writing means and a reading means. However, the writing means is not used after a necessary data has been written in. Therefore the sequence controller having both writing means and reading means is very expensive. In order to remove such disadvantages, a sequence controller having a single function should be provided. Moreover, in order to carry out the programing and changing thereof, skilled programmers are required. Therefore, in case that there is no proper person to meet such purposes, the programing is often made by third person, which will result in the leakage of user's original technical know-how to the outside.
If such a sequence controller is divided into a write-only sequence controller and a read-only sequence controller, and if the write-only sequence controller is detachably provided with a read-only memory EPROM and the read-only sequence controller is adapted to be operated by attaching the EPROM to produce an output of data in the EPROM, data may be written in a plurality of EPROMs by one write-only sequence controller. Therefore, an economical control system is provided.